kubuntu won't ping my debian server

[Dexter Filmore]

I'm a bit lost with name resolving on my local net.
Got three machines:
server (debian etch)
desktop1 (dual etch/kubuntu)
desktop2 (etch)

Now - all machines could ping each other fine. server and desktop1 are 
assigned fixed IPs in m0n0wall, desktop2 gets dhcp.

as long as all were debian I could ping all hosts from all hosts by name. 
Now when running Kubuntu on desktop1 I can't ping the server no more, only by 
IP.
(I can perfectly ping desktop1 from the server tho.)

I have no local DNS set up unless m0n0wall provides it - I was told it didn't. 
Question is: when all the debians are up, how do they actually resolve their 
names when there's no DNS around?
And of course: why doesn't it work from Kubuntu?

Dex

-- 
-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GCS d--(+)@ s-:+ a C++++ UL++ P+>++ L+++>++++ E-- W++ N o? K-
w--(---) !O M+ V- PS+ PE Y++ PGP t++(---)@ 5 X+(++) R+(++) tv--(+)@ 
b++(+++) DI+++ D- G++ e* h>++ r* y?
------END GEEK CODE BLOCK------

http://www.vorratsdatenspeicherung.de